Immunocytochemical studies of Salmonella Typhimurium invasion of porcine jejunal epithelial cells

Abstract

Although infection of pigs with Salmonella Typhimurium represents a serious problem, most studies on Salmonella infection have been carried out in other species. The purpose of the current study was to examine the route(s) of entry of Salmonella Typhimurium in pigs, using a jejunal loop model. The infection process was followed over 240 min using single to triple immunocytochemical detection of Salmonella and intestinal cell markers. Salmonella invasion was observed in both cytokeratin-18-positive and -negative cylindrical absorptive cells within 5-10 min. Subepithelial invasion of ordinary villi was consistently less marked than invasion of the subepithelial layer of Peyer's patches. Our results show that several epithelial cell types were invaded by Salmonella, and that Peyer's patches represent the main portal of entry in early Salmonella infection. Additionally, infection was associated with alterations in the keratin and F-actin cytoskeleton of intestinal epithelial cells, probably reflecting toxin-mediated actions. Such changes were confined to the proximal region of the jejunum, demonstrating a regional heterogeneity of intestinal epithelial cell responses to Salmonella infection.

Rectal stenosis in pigs associated with Salmonella Typhimurium and porcine circovirus type 2 (PCV2) infection

“…Clinical disease is mainly associated with Salmonella Choleraesuis (S. Cholerasuis) and Salmonella Typhimurium (S. Typhimurium) (Schauser et al 2004, Griffith et al 2006, Brown et al 2007, Kich 2007. Transmission can occur by contamination of feed, water or the surroundings where the organism can be ingested or inhaled.…”

Evaluation of respiratory route as a viable portal of entry for Salmonella in poultry

“…Several epithelial cell types are shown to be invaded by Salmonella, and Peyer's patches represent the main portal of entry in early Salmonella infection. 129 The process of invasion and subsequent infection is widely accepted to be pathogen-driven, and host cells have a minor or no role to play, whereas in the respiratory system, age-related developmental differences in the nasal-associated lymphoid tissue and BALT structures may have functional consequences with respect to the pathogenesis of Salmonella. The disrupted epithelial barrier and previously described endocytosis could be a relatively easy portal of entry for Salmonella.…”

Intestinal lesions in pigs affected with postweaning multisystemic wasting syndrome

“…Sections were processed for IS anti-PCV2 (Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, USA, Sorden et al 1999) by the streptavidin-biotin immunoperoxidase (Dako, Carpinteria, CA) technique using diaminobenzidine (Dako, Carpinteria, CA) as chromogen. Similarly, selected sections were also tested by IS against Lawsonia intracellularis (Department of Veterinary Pathobiology, University of Minnesota, USA, Guedes et al 2002) Schauser et al 2004), porcine parvovirus (VMRD Inc., Pullman, USA, , and porcine coronavirus (Serotec, Whashington, USA). Selected fecal samples (n=12) were also screened for the presence of rotavirus groups A, B and C, and enteric calicivirus (Norovirus and Sapovirus genera) by reverse transcription polymerase chain reaction (RT-PCR) assay.…”